title: Antimony speciation in soils: improving the detection limits using post-column pre-reduction hydride generation atomic fluorescence spectroscopy (HPLC/pre-reduction/HG-AFS).
abstract: HG-AFS is highly sensitive and low cost detection system and its use for antimony chemical speciation coupled to HPLC is gaining popularity. However speciation analysis in soils is strongly hampered because the most efficient extractant reported in the literature (oxalic acid) strongly inhibits the generation of SbH(3) by Sb(V), the major species in this kind of matrix, severely affecting its detection limits. The purpose of this research is to reduce the detection limit of Sb(V), by using a post column on-line reduction system with l-cysteine reagent (HPLC/pre-reduction/HG-AFS). The system was optimized by experimental design, optimum conditions found were 2% (w/v) and 10°C temperature coil. Detection limits of Sb(V) and Sb(III) in oxalic acid (0.25 mol L(-1)) were improved from 0.3 and 0.1 μg L(-1) to 0.07 and 0.07 μg L(-1), respectively. The methodology developed was applied to Chilean soils, where Sb(V) was the predominant species.
authors.affiliation: Laboratorio de Química Analítica y Ambiental, Instituto de Química, Pontificia Universidad Católica de Valparaíso, Avenida Parque Sur 330 Curauma, Valparaíso, Chile. waldo.quiroz@ucv.cl
authors.forename: Waldo
authors.initials: W
authors.lastname: Quiroz
authors.forename: David
authors.initials: D
authors.lastname: Olivares
authors.forename: Manuel
authors.initials: M
authors.lastname: Bravo
authors.forename: Jorg
authors.initials: J
authors.lastname: Feldmann
authors.forename: Andrea
authors.initials: A
authors.lastname: Raab